The following is an article from The Annals of Improbable Research.
by Laura E. Campbell, Shields Library, University of Califonia, Davis, Califonia, and
Morgan T. Lockwood, Davis, Califonia
The napkins provided in fast food restaurants vary in their abilities to sop up stains. As a service to both the public and the restaurants, we measured the sop-up efficiency of the napkins provided at these establishments.
Assessing the Napkins
We tested napkins from five competing fast food establishments:
Carl's Junior
Taco Bell
Jack in the Box
McDonald's
Burger King
Kentucky Fried Chicken
The tests used maraschino cherries, the juices of which produce red rings on napkins. These rings are easy to measure and compare.
Figure I. Napkins from Carl's Junior. Taco Bell (T), Jack In The Box (J ), McDonalds (M). Burger King (B) and Kentucky Fried Chicken (K ). Each napkin Sopped lip the juices from four half-cherries. For each napkin, the four radius lengths were averaged. The average sop area was then calculated and compared with the total napkin area to obtain the napkin sop factor.
We used cherries that were 19-20 millimeters in diameter. Each cherry was hCllved at its equator. We used a Solingen 20 centimeter French-bladed kitchen knife. When this was completed, 2 cherries- that is, four cherry halves-were placed on each folded napkin (see Figure 1). After 5 minutes had elapsed, we measured the size of the circles of red moisture that had soaked through to the back of each napkin. (see Table 1).